Got in my car the other day when I got back from visiting family/friends for a week and my ABS Inop light came on around 15mph (same time the ABS system "turns on": 15-20mph, right before it shifts to 2nd, and without touching the brakes). It stays on steady while I'm driving. No other lights come on with it such as LowTrac or Brake and my cruise control works. Light comes on at the same time consistently every time I drive, no once in a while or on then off business.

I have NEVER had the ABS Inop light come on while driving, and the fact it's now on steady after the car sat for almost a week concerns me (brother drove it twice, but the light never came on for him and it drove fine).

I haven't tested the ABS for operation yet since it's been so dry, and I'm really hoping it's not a failed motor/solenoid in the system. I did replace my third brake light bulbs about a month ago. Cruise control works, so if it's a WSS it'd have to be in the front, right?

Any other simple tests to run before tearing into it or paying $100 to have the codes read?

Ground wire looks okay—no corrosion, solid connection to chassis, and doesn't appear to have any kinks or breaks in the insulation. Fuses all look good (ABS VI, ABS Bat, and ABS Ign don't look like they've ever even been hot.)

Fluid level is good and none of the metal lines going into or out of the ABS unit are corroded or leaking. Connections at the unit are all tight.

Quote:

Originally Posted by NavyVet

Crusie control has absolutely noithing to do with ABS or wheel speed sensors.
There is / are sensors in the back also. 2 with drum brakes, 1 with disks and limited slip.

Check the sensor connections.

I was under the impression that if one or both speed sensors went bad on back that cruise wouldn't work (or at least not correctly)… this was just something I read when trying to figure out what all to check, so I thought I'd mention it.

The connectors in front looked good, so I'll be checking the back momentarily.

I had a bad ABS wheel sensor in my bird that caused the ABS INOP light. You can get the computer scanned to find what the issue is with the ABS system, but it usually costs. In my experience auto parts stores can not scan the ABS system and shops charge about $40 to do it.

__________________2001 Trans Am WS6|Fbody of the Month April 2011 for 2002 Camaro|

Thought that's what I did. The front ones are built into the wheel hubs (the only electrical connector on the backside of the wheels) and the connection for the rear is mounted on top of the differential (mine's an open-diff with drums) with a line going to each wheel, correct? They all look okay as far as I can tell without having the car on a lift to get a real close look at them.

Will probably contact my mechanic to see if he can get a readout tomorrow if don't see anything else tonight. Best thing about a small town is that you always have at least one old family friend in any business

Update: Mechanic checked the codes and found no current codes. History code was front left wheel sensor shorted to ground.

Before buying new wheel hubs, I decided to check my brake lights since ground problems with them can apparently trigger the ABS light.

Everything checked out except my left rear sidemarker—I found water standing in it and there was a broken contact in the bulb socket (contact wasn't totally gone and looked like it still touched the bulb contacts okay… going to replace anyway since it looks like there's been some corrosion from the water). Bulb looked good but wouldn't turn on—put in a new bulb and it still didn't work. Is this bulb part of the circuit that causes the ABSInop light when the third brake lights go? I assume because it would probably connect to the main harness at the same place as the brake lights.

Plan to replace the hub anyway since I'm pretty sure they're original (WOW!). Just wanted to have everything laid out for troubleshooting purposes for others in the future. Figure on replacing both hubs as preventative maintenance.

Hub choices are:
Moog (3 year warranty—$76 each after discount)
Timken (1 year warranty—$115 each)
SKF (1 year warranty—$160 each OR 2 NOS ones for $130 on eBay but no warranty)

The eBay set is really tempting, but then again SKF had some trouble with "grey market" and counterfeiting back in '02 and there's not really a way to tell a genuine part from a counterfeit.

Try Amazon. I think the moog ones would be good. Im going to check Amazon and see what I can find.

I checked for part number 513090 and their best on a quality bearing was about $125 (Timken) while the others were $145. Free shipping is nice though. Only had Timken, BCA, National, and Precision (crap) show up.

Hang the eBay set for $55… I did research on fakes and when I asked the guy if there was a way to tell he said, "I've seen fakes and you can tell by looking at them, plus I know these came from SKF. Good luck with the $160 ones."

So here's a challenge for everyone: which of the following is the fake bearing?